---
layout: docs
page_title: Install Nomad as a Windows service
description: |-
  Learn how to run Nomad as a Windows service. Register Nomad with the Windows Service Control Manager. Configure Nomad to log to file, and increase the non-interactive desktop heap size.
---

# Install Nomad as a Windows service

Nomad can be run as a native Windows service. In order to do this, you will need
to register the Nomad application with the Windows Service Control Manager using
[`sc.exe`], configure Nomad to log to a file, and then start the Nomad service.

~> **Note:** These steps should be run in a PowerShell session with Administrator
capabilities.

## Register Nomad with Windows

[Download] the Nomad binary for your architecture.

Use the [`sc.exe`] command to create a Service named "Nomad". The binPath
argument should include the fully qualified path to the Nomad executable and any
arguments to the nomad command: agent, -config, etc.

```plaintext
sc.exe create "Nomad" binPath="«full path to nomad.exe» agent -config=«path to config file or directory»" start= auto
[SC] CreateService SUCCESS
```

If you receive a success message, your service is registered with the service
manager.

If you get an error, please verify the path to the binary and check the
arguments, by running the contents of `binPath` directly in a PowerShell session
and observing the results.

## Configure Nomad to log to file

Because Windows services run non-interactively and Nomad does not log to the
Windows Event Viewer, you will need to configure file-based logging in Nomad.

To do this, set the [`log_file`][logging] argument in your Nomad configuration
file or in the binPath argument of the [`sc.exe`] command used to register the
service.

## Start the Nomad service

You have two ways to start the service.

- Go to the Windows Service Manager, and look for **Nomad** in the service name
  column. Click the _Start_ button to start the service.

- Using the [`sc.exe`] command:

  ```plaintext
  sc.exe start "Nomad"

  SERVICE_NAME: Nomad
        TYPE               : 10  WIN32_OWN_PROCESS
        STATE              : 4  RUNNING
                                (STOPPABLE, NOT_PAUSABLE, ACCEPTS_SHUTDOWN)
        WIN32_EXIT_CODE    : 0  (0x0)
        SERVICE_EXIT_CODE  : 0  (0x0)
        CHECKPOINT         : 0x0
        WAIT_HINT          : 0x0
        PID                : 8008
        FLAGS              :
  ```

The service automatically starts up during/after boot, so you don't need to
launch Nomad from the command-line again.

## Increase the non-interactive desktop heap size

If you run Nomad as a Windows service and you intend to run many allocations,
such as more than 50, you may encounter issues with Windows terminating Nomad
plugin processes with errors such as `exit status 0xc0000142` appearing in the
logs. This is due to Nomad's inability to spawn more concurrent processes, and
you may fix this by manipulating the value of
`HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session
Manager\SubSystems` Windows registry key.

This key has a `Windows` value which in turn has a `SharedSection` parameter
that accepts a value of three comma-separated integers, for example,
`1024,20480,768`. The first integer indicates the maximum size of the
system-wide heap, the second is the size of each desktop heap, and the third is
the size of the desktop heap that is associated with a noninteractive Windows
instance. All values are in kilobytes. For large Windows nodes that run large
numbers of allocations, we recommend setting the final integer value to 2048 or
4096 kB. Remember that any registry change requires restarting Windows, a
restart of Nomad service is not sufficient.

[`sc.exe`]: https://msdn.microsoft.com/en-us/library/windows/desktop/ms682107(v=vs.85).aspx
[download]: /nomad/downloads
[logging]: /nomad/docs/configuration#log_file
